Don't Wake My Parents.
Young man meets a girl one night and ends up walking her home. When they get to her house he asks if he can come in for a coffee, she says yes but you'll have to be quiet so as not to wake my parents. During the coffee he asks to use the loo, she says you can't, it's upstairs, you'll wake my parents. He says he's desperate. She says you'll have to use the kitchen sink. Five minutes later he sticks his head round the door and says " You got any toilet paper"